J. Antibiotics 28, 247, 1975 describes the production of lipiarmycins from Actinoplanes deccanensis nov. sp. A/10655. Structural study of lipiarmycin A3, A4, B3 and B4 is described in J. Antibiotics 36, 1312, 1983 and J. Antibiotics 41, 308, 1988. Another article J. Antibiotics 39, 1407, 1986 describes strain Micromonospora echinospora subsp. armeniaca subsp. nov. KMR-593 to produce five antibiotics compounds named as clostomicin A, B1, B2, C and D. Another complex of six antibiotic compounds, named as tiacumicins (A-F), is produced from Dactylosporangium aurantiacum subspecies hamdenensis as described in J. Antibiotics 40, 567, 1987. Lipiarmycin A3, Clostomicin B1 and Tiacumicin B are the same compound, alternatively known as fidaxomicin, and have potent activity against Clostridium difficile. 
U.S. Pat. No. 4,918,174 discloses six tiacumicin compounds (tiacumicin A-F) of the following chemical structure (I). Tiacumicin A-F has different substituent at R, R1 and R2 positions.

Antimicrob. Agents Chemother. 1991, 1108-1111 describes potent activity of tiacumicins, particularly tiacumicin B against Clostridium difficile. 
U.S. Pat. No. 4,918,174 and J. Antibiotics, 1987, 575-588 describe production and isolation of tiacumicin B by aerobic fermentation of Dactylosporangium aurantiacum subspecies hamdenensis. Fermentation is carried out using glucose and soybean oil as a carbon source; and soybean flour, beef extract or peptone as a nitrogen source. Temperature is maintained in a range of 25 to 35° C. and pH is set in a range of 6 to 9. The filtered broth is extracted with ethyl acetate and is concentrated to give oily residue. The residue is purified by partitioning between solvents and chromatography. This process produces Tiacumicin B in maximum yield of 4.24 mg/L broth.
U.S. Pat. No. 7,507,564 provides an improved process for the preparation of fidaxomicin which gives better yield of fidaxomicin as compared to process disclosed in U.S. Pat. No. 4,918,174. The process of U.S. Pat. No. 7,507,564 gives more than 50 mg/L broth yield of fidaxomicin. According to U.S. Pat. No. 7,507,564, it is essential to use adsorbent resin in nutrient media during fermentation which leads to increased yield of fidaxomicin.
There is a need to develop a simpler process which provides increased yield of fidaxomicin.
US2010/0009925 describes stereomerically pure fidaxomicin, which contains >90% pure R isomer. However, it does not provide any method for its preparation, but referred to a process disclosed in U.S. Pat. No. 7,507,564. Fidaxomicin is chemically represented by structure of formula (II).
